Display unit for storing and displaying heated goods

ABSTRACT

A display unit for storing and displaying heated goods according to the invention that comprises walls, multiple shelves, an air duct, an air forcing apparatus and air temperature regulating means. At least part of the walls of the display unit delimits a chamber with an open front side. The multiple shelves each comprise an upper placing side. The multiple shelves each extend substantially horizontally in the chamber and are provided above each other to define an individual storage space above each shelf. The air duct extends from an inlet opening to multiple outlets whereby the outlets each define a flow direction. At least one of the multiple outlets flows to a corresponding storage space. The flow directions of the multiple outlets point away from the corresponding placing sides.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the National Stage of International Application no. PCT/NL2009/000142 filed Jul. 2, 2009, which claims the benefit of Netherlands patent application number 2001749 filed Jul. 2, 2008 and U.S. provisional patent application No. 61/077,578 filed Jul. 2, 2008, the contents of which are incorporated by reference as fully set forth herein.

FIELD OF THE INVENTION

The invention relates to a display unit for storing and displaying heated goods according to the introduction to claim 1. Such a display unit is often used to display products in an attractive manner to possible users in which the users have a good view of the goods and they can take the goods easily without having to open a door of the display unit. The goods concerned can be consumption-ready hot food items such as hot snacks, chicken products, soups or drinks.

BACKGROUND

WO-A1-2007/053002 discloses a display unit for storing and displaying heated food. The display unit comprises a chamber with an open front side provided with shelves. The food can be placed on the shelves. The display unit is provided with an air duct that extends to multiple outlets from an inlet opening at the top of the chamber via a fan and heating elements. The outlets are distributed over the bottoms of the shelves. Hot air is blown in the direction of the food on the shelves from these outlets.

A disadvantage of the known display unit is that the quality of the food can be influenced negatively.

SUMMARY

The object of the invention is to at least eliminate the disadvantage of the known display unit or, at any rate, to provide a useable alternative. In particular, the object of the invention is to provide a display unit in which goods that are stored in the display unit are less susceptible to be affected negatively in quality due to the operation of the display unit itself.

A display unit for storing and displaying heated goods according to the invention comprises walls, multiple shelves, an air duct, an air forcing apparatus and air temperature regulating means. At least part of the walls of the display unit delimit on a chamber with an open front side. The multiple shelves each comprise an upper side. The goods can be placed on the placing side or, in a particular embodiment, be suspended there just above. The multiple shelves each extend substantially horizontally in the chamber and are provided above each other to define an individual storage space above of each shelf. The air duct extends from an inlet opening to multiple outlets, wherein the outlets each define a flow direction for flowing air. At least one of the multiple outlets flows to each of the storage spaces. The flow direction of at least one outlet points away from a placing side to the rear. Preferably, under a sharp angle with respect to the placing side. For example, under an angle of at most 80° and at least 30°. Herewith, the substantially entire air flow flows into the storage space concerned. This may advantageously ensure that an air screen is created per storage space to protect the goods on the placing side. This, additionally provides a further design freedom for the configuration of the display unit. Conventional air screens of different storage spaces may be aligned to each other in a vertical direction, but now a display unit may comprise multiple storage spaces positioned in a staggered manner relative to each other according to the invention. Due to the inventive flow direction, the heated air is not blown to the goods on the shelves. In comparison with the prior art, the heated air will generally have a lower speed at the location of the goods. This may have some advantages for the goods on the shelves. For example, moisture-containing goods will dry out less quickly, goods with a soft surface will dent less quickly and sensitive goods will absorb dust particles or other hazardous particles less quickly. Due to the lower air speed, packaging of such goods does not longer have to comply with relatively high requirements. It has appeared that it may be advantageously possible to create a more or less stationary zone on top of the placing side of the shelf having the air flow flowing in under an angle. This will ensure that the quality retention of the goods on the placing side can be even better safeguarded.

In an embodiment of the display unit according to the invention the storage space is closed at the rear. Preferably, the storage space is only open at the front side. This will ensure that an air flow that comes in from a front side in the storage space, returns and again flows out at the front side of the storage space. The incoming air flow will advantageously fill the storage space and dispel colder air. The air flow may preferably leave the storage space through the upper region past the bottom side of an above positioned shelf. In particular, colder air may be dispelled in the upper region of the storage space in a direction to the front side of the storage space.

In an embodiment of the display unit according to the invention the placing side is at least partially airtight. This will ensure that the distance of the air flow can advantageously be longer before the air flow comes in contact with the goods on the placing side. This will advantageously ensure that the drying-out of goods is counteracted. In particular, the placing side where normally the goods are positioned is airtight. Preferably, the entire placing side is airtight e.g. by producing the shelf from a folded flat sheet. A grill may have been provided on the airtight closed shelf to place the goods.

Preferably the shelf is black. This will ensure that adequate heat emission can be obtained. The shelf, for example, may be made of stainless steel wherein a heat-emitting surface may have been provided with a black layer, for example, a black coat, for example, added by powder coating.

In particular, at least one of the shelves comprises a front edge along which at least one of the multiple outlets extends. Such a position for the outlet is advantageous because it is relatively easy to realize that goods are not placed on the outlet.

Especially, the flow direction of the at least one outlet that extends along the front edge points upwards and to the rear. Thus, heated air is blown away from the placing side of the shelf into the storage space.

Herewith an air screen for the storage space is formed simultaneously.

In an embodiment the outlet is slotted. This will advantageously ensure that an air flow can be obtained that is uniformly blown over the width of a storage space. The air screen may advantageously comprise an air flow that is as continuous as possible over the goods in the storage space over a width such that all the goods on the shelf are heated as uniformly as possible.

In an embodiment according to the invention the shelf comprises a pressure chamber which is in fluid communication with the outlet. Preferably, the pressure chamber extends over substantially the entire length and/or width of the shelf. The presence of the pressure chamber has the advantage that a more silent air flow can be obtained to the storage space. Pressure fluctuations can be dampened by the pressure chamber. A pressure fluctuation can, for example, originate from the fan or may be caused by a partially covered outlet at the front edge of the shelf. The pressure build-up in a storage space may again be built up more smoothly with the aid of the pressure chamber. The air flow and, therefore, the temperature regime in a storage space can advantageously be better controlled by the presence of the pressure chamber in the shelf.

In an embodiment according to the invention the pressure chamber may be formed by the top, bottom ad side walls of the shelf. The shelf may, for example, be formed by a folding operation. Preferably, the top, bottom and side walls of the shelf are airtight. The shelf may have advantageously been constructed in such a way that leak gaps are avoided as much as possible.

In an embodiment of the display unit according to the invention the pressure chamber may be a separate chamber of a hollow shelf. The shelf may, for example, comprise a cavity with a partition. The partition may extend over substantially the entire width of the shelf. The partition may subdivide the cavity of the shelf into a heating chamber and a pressure chamber. Preferably, the pressure chamber is located at the rear of the shelf so that an air supply means, for example, a pipe, can be connected to the pressure chamber. The pressure chamber may comprise outlets which, preferably, are distributed uniformly on a side. An air flow may be uniformly distributed in the direction of the front side of the shelf due to uniformly distributed outlets.

In a particular embodiment, the pressure build-up in the display unit can be further improved by using a fan with a larger pressure build-up of, for example, at least 500 Pa positive pressure. A disruption of the air flow can advantageously be better absorbed by using a more powerful fan so that an increase of a flow resistance will not directly result in an unacceptable drop in pressure.

In a particular embodiment, the display unit may comprise multiple fans. The fans may be arranged in parallel, for example, distributed over the width of the display unit.

In a particular embodiment, the display unit is constructed modularly. The display unit may be constructed from unit sections which are arranged side by side. Every unit section may comprise for example, 3, 4 or 6 shelves. Every unit section may have its own fan. A unit section may, for example, have a width of 60 cm, 100 cm or 120 cm. A display unit can thus advantageously be provided modularly in different widths.

In an embodiment according to the invention the display unit may be modularly constructed in height. The shelves of a display unit may have the same dimensions which enables a modularly constructed display unit with, for example, 3 to 6 shelves which can be realised easily. The production process of the display unit may advantageously be simplified with this.

In an embodiment according to the invention at least one shelf comprises a heating element for heating a passing air flow. In a particular embodiment of the display unit according to the invention every shelf comprises a heating element. A considerable energy saving may be achieved advantageously when heating and maintaining the display unit at a certain temperature due to the heating element in the shelf. An energy saving of approximately 20% has been proven to be achievable. Moreover, the temperature of the exiting air may be higher per shelf in comparison with a centrally heating display unit, which means that the temperature regime may advantageously be better controlled.

Preferably, the heating element has at least one flat side. The heating element is, for example, sheet- or strip-shaped. Preferably, the heating element has been positioned in the pressure chamber in which the dimensions of the heating element substantially corresponds with the width and length dimensions of the pressure chamber. This may ensure that a passing air flow can be heated uniformly over the width of a shelf.

In an embodiment of the display unit according to the invention the heating element has an upper and lower side that generates heat in such a way that heat may be emitted to both an upper and lower region. In a particular embodiment, the heating element has on the lower side a greater heat-generating capacity than on the upper side.

The upper side may, for example, be partially insulated, for example, by a larger air space in-between the placing side of the shelf and the heating element than in-between the bottom side of the shelf and the heating element. Preferably, the heating element is positioned closer to the bottom side than to the placing side of the shelf. An air flow that passes at the bottom side of the shelf may be heated advantageously by the heat-generating lower side. This will ensure that an air flow is heated in the lower storage space. Because the heating element is positioned closer to the bottom side than to the placing side, more heat may be emitted at the bottom side of the shelf. More heat radiation may be generated at the bottom side of the shelf due to the positioning of the heating element near the bottom side of the shelf. Herewith, it advantageously may be prevented that goods lose quality, for example, dry up too quickly, due to an excess of heat supply to the placing side. This advantage is especially important with respect to pasta.

In an embodiment of the display unit according to the invention the display unit comprises a heating element for heating a passing air flow in an upper region. The heating element is preferably positioned on top of the highest storage space. Preferably, the heating element is suitable for heating an air flow in the top storage space. The passing air flow in the top storage space may, for example, be heated by radiation heat. Preferably, the heating element is positioned downstream adjacent to the inlet opening. Herewith, an air flow can be preheated before it is supplied to a fan.

Heating the passing air flow towards the fan may, for example, be achieved through convection. Heating by the heating element in the upper region of the display unit may have the advantage that temperature fluctuations in the overall air flow through the display may be counteracted. Temperature fluctuations can be dampened as much as possible. Preferably, the heating element has a flat side, for example, the heating element may be sheet-shaped.

Preferably, the outlet is provided in an elongated flow unit, which is provided at the front edge of the shelf. Such a flow unit can at the same time form a border at the front edge of the shelf to ensure that goods cannot slide off the shelf.

In particular, a front wall section of the elongated flow unit is so much wider than a rear wall section of the elongated flow unit that the front wall section covers the outlet in the vertical direction. Herewith, the risk may be reduced that objects fall unintentionally in the outlet or that they cover the outlet, which could damage the correct operation of the display unit.

In an embodiment, all outlets discharge into the storage spaces. Surprisingly, herewith less air may be required to achieve a correct operation of the display unit in comparison with a prior art type of display unit in which air may be required for the creation of an air screen at the front of the display unit. Moreover, one fewer air duct and fan may be required than with a prior art type of display unit that has a central air screen and outlets in the storage space.

The invention, moreover, relates to a method or heating products in a storage or display unit. The display unit has a rear wall and side walls. The display unit has, further at least one shelf.

A storage space has been defined for storing products above the shelf.

Characteristic of the method according to the invention is that an air flow is guided through a hollow shelf from the rear to the front and that substantially the full air flow is supplied to the storage space from a front edge of the shelf. Except on the front and rear side, the hollow shelf is preferably provided fully airtight. Due to the method it may be achieved advantageously that products in the storage space are less quickly negatively affected. The products, for example, dry out less quickly due to the relatively slowly passing air flow. The discharged air flow to the storage space may advantageously form an air screen over the products on the shelf.

In an embodiment according to the invention the air flow is supplied upwards and backwards from the front edge in the storage space by at least one outlet. The outlet may be formed in such a way that a flow direction is determined in which the air flow is supplied under a sharp angle with respect to the shelf in the storage space.

In an embodiment of the method according to the invention the supplied air flow in the storage space returns and the air flow is discharged at the front side of the storage space. In this case, the air flow passes through the storage space from the front to the rear and again from the rear to the front. This will advantageously ensure an adequate temperature distribution in the storage space and the storage space may be maintained stable.

In an embodiment of the method according to the invention the discharged air flow is guided upwards at the front side of the display unit once it leaves the storage space. To boost the flow, an inlet opening can be provided in an area that lies on top of the display unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further explained by the appended drawing. The drawings show a practical embodiment of the invention, which may not be considered in a limiting manner. Particular detail features may also be viewed as characteristic of the invention in general apart from the shown embodiment. The invention will be further explained by basis of the appended drawing in which:

FIG. 1 illustrates a heating display unit according to the invention in a perspective view thereof;

FIG. 2 illustrates a removable shelf of the heating display unit from FIG. 1;

FIG. 3 illustrates a detail of the shelf of FIG. 2;

FIG. 4 illustrates a heating display unit according to the invention with a partially exploded view of the top shelf; and

FIG. 5 illustrates an exploded view of a hollow shelf with a heating element.

DETAILED DESCRIPTION

FIG. 1 illustrates a heating display unit according to the invention that is designated in its entirety with reference number 1. The heating display unit 1 comprises a base 2 for setting up the heating display unit 1 on a surface. The heating display unit 1 comprises multiple walls 4 including a bottom that cannot be seen in the figure, side walls 6, a top wall 8 and a rear wall that cannot be seen in the figure. At least part of the walls 4 is at least partially double-walled. In this embodiment, the top wall 8 is fully double-walled and the side walls 6 are partially double-walled. The side walls 6 are also partially transparent in this embodiment for displaying a chamber 10 in the inside of the heating display unit 1. The chamber 10 is enclosed on five sides by the inside of the aforementioned bottom, side, rear and top walls of the heating display unit 1. The chamber 10 is substantially open on a front side of the heating display unit 1 to offer the user immediate access to the chamber 10.

In the chamber 10 there are multiple shelves 12, in this case four shelves 12, that can be provided with placing grills 13. The four shelves 12 together and with the inside of the rear wall define four storage spaces 14 for storing and displaying goods such as solid and liquid food. The storage spaces 14 are open towards the front for easy access for a user. The partially double-walled side walls 6 of the heating display unit 1 comprise side units 16.

In FIG. 1 the left side unit 16 is partially illustrated in an exploded view to illustrate a partition 18 and an air forcing apparatus, in this case, a fan 20. Partition 18 extends substantially vertically over substantially the entire side unit 16, which is schematically illustrated by a vertical dotted line. The partition 18 divides the side unit 16 in a first pass-through space 22 and a second pass-through space 24. The first and the second pass-through spaces are connected with each other through a passage 26, wherein this passage 26 in this embodiment example is provided with the fan 20. The in this case second pass-through space 24 is provided with air temperature regulating means, in this case, heating elements 28.

The heating display unit 1 is further provided with an inlet opening 30. The inlet opening 30 can be found in the top wall 8 of the heating display unit 1 and is provided near the front hereof. The inlet opening 30 is in fluid communication with both the first pass-through spaces 22 of the two side units 16 via the double-walled top wall 8.

The shelves 12 each comprise an air discharge space 32 as illustrated by the partially exploded view of the shelf 12 of FIG. 2. In this embodiment example the air discharge space 32 is formed by substantially the entire hollow inside space of the shelf 12. The air discharge space of each shelf 12 is provided with connection openings 34 that each connects to a corresponding (not separately illustrated) connection opening of the second pass-through space 24 in the assembled state of FIG. 1.

Every shelf 12 in this embodiment example is provided with an outlet 36 near a front edge 35, in this case, a slotted-shaped outlet 36 that extends parallel to the front edge 35. The outlet 36 extends over substantially the entire width of the shelf 12. In this example the outlet 36 is formed by a flow unit 38, wherein this flow unit 38 has a small thickness relative to its length and width. FIG. 3 illustrates that a front wall section 39 of the flow unit 38 is that much wider than a rear wall section 40; that the front wall section 39 covers the outlet 36 in vertical direction. The hollow inside space of the flow unit 38 is through connected to the air discharge space 32.

The first pass-through space 22, the second pass-through space 24 and the air discharge space 32 together form an air duct that extends from the inlet opening 30 to the outlets 36.

The shelf 12 comprises a bottom side 41 and a top side 42. The top side 42 acts as a placing side that is suitable to place goods on such as food. The bottom side 41 of three of the four shelves 12 together define with the top side 42 of the next shelf 12 that is under the shelf concerned one of the storage spaces 14 of the heating display unit 1 in each case. The top of the storage spaces 14 is defined by the bottom side of the top wall 8 and the top side 42 of the top shelf 12. Each of the storage spaces 14 is delimited on its rear by the inside of the rear wall and is open at its front side.

The shelves 12 are made of a heat-conducting material, in particular, metal, particularly, stainless steel. The metal placing side 42 of the shelf 12 is set up to transfer heat through conductivity to food that is located on the placing side 42 of the shelf 12.

When in use, air is suctioned via the inlet opening 30. The suctioned air comprises partially recirculated air from the chamber 10 and partially air that has entered inside through the open front of the chamber 10 to supplement the hot air that has escaped from the chamber 10. The suctioned air is divided in the double wall of the top wall 8 in a non-illustrated manner into two air flows that each is guided through the first pass-through space 22 concerned of the side unit 16 to the rear and downwards. The air is thereby suctioned by the fan 20 that also ensures that the air of the first pass-through space 22 is guided to the second pass-through space 24. In the second pass-through space 24 the air is heated by the heating elements 28 up to approximately 80° C. The heated air enters from the second pass-through space 24 via one of the connecting openings 34 into the air discharge space 32 of each of the shelves 12 in each case. From the air discharge space 32, the heated air heats air and, if required, food present on the placing side 42 via the placing side 42 as well as air that is present under the shelf 12 via the bottom side 41. Subsequently, the hot air enters into the flow unit 38 where it exits through the outlet 36 to the outside.

The hot air that exits the outlet 36 forms a screen of hot air. The flow direction of the outlet 36 and, with that, the direction of the hot air screen, is indicated schematically in FIG. 1 with arrows 50. Each of the air screens has a flow direction 50 that points away from the placing side 42 of the shelf 12. In this embodiment example the flow direction 50 of every air screen points to the rear and upwards. The flow direction 50 of most shelves 12 amounts to fifty-five degrees relative to a horizontal face. The outlet 36 of the bottom shelf 12 has a flow direction of forty-eight degrees relative to a horizontal face. In general, the flow direction of the outlet 36 points at least partially upwards or away from the shelf 12. Moreover, the flow direction points into the storage space 14 and in this embodiment example of the front edge of the shelf 12 to the rear.

An air screen with flow direction 50 for the storage spaces 14 makes the entrance of cold ambient air difficult. Because each time an air screen for every storage space 14 is created according to the invention, an effective air screen is attained at a flow speed that is considerably lower than when only one air screen would have to be formed for the entire chamber 10 as occurs in prior art.

Moreover, the individual air screens ensure that each storage space 14 is protected from the outside air just as effectively as every other storage space 14. Should there only be one air screen as in prior art, the effectiveness in the direction of the air screen would be reduced whereby storage spaces that can be found further away from the outlet of the single air screen would be less protected.

Because the air screens are partially directed towards the rear according to the flow direction 50, that is to say, the storage spaces 14 are pointed at, there is an air circulation in the storage spaces that is indicated schematically with arrows 52. The circulating hot air heats food or other goods that may be found on the shelves 12 through transfer. A relatively powerful air flow is required for forming the air screens. Because this powerful air flow of the air screen is not directed towards the food or other goods but substantially the circulating air 52 comes into contact with the food or other goods, the air speed where the food or other goods can be found is less high. This will ensure that the goods will not deteriorate as much due to drying out or another effect of the flowing air will take place than when (part of) the air screen would be directed directly on to the food.

Part of the circulating air 52 will exit the storage spaces 14 as indicated schematically through arrows 54. Because the front edge 35 of each of the shelves 12 is positioned towards the rear relative to the front of the heating display unit 1, the exiting air 54 will, to an important extent, remain within the chamber 10 and will again enter the first pass-through space 22 via the inlet opening 30. Thus, the air in the first pass-through space 22 has to be heated to a lesser extent than when only ambient air would be suctioned. Moreover, the exiting hot air provides a buffer in the space in-between the front edge 35 of the shelves 12 and the farthest away front of the heating display unit 1. This buffer reduces the heat loss of the storage spaces 14 to the environment outside the display unit 1.

Various variants are possible within the scope of the invention. The outlets are provided on the placing side of the shelf. The outlet does not need to be a slotted-shaped opening that extends as one opening over substantially the entire width of the shelf. A comparable effect can be achieved through a series of outlets that extend substantially along a line parallel to the front edge of the shelf. The outlet can also have been provided directly in the top side of the shelf in which the required outlet is achieved in an upwards and to the rear direction of the flowing hot air through partitions and/or fins. In the illustrated embodiment example the flow unit is provided along the farthest away front edge of the shelf. It is also possible that the flow unit extends at a distance from the front edge of the shelf although parallel in which part of the shelf extends in front of the flow unit. This part that extends in front of the flow unit is small relative to the depth of the shelf and is not a part of the shelf that is used to place food on. The part of the shelf that is used to place food on is referred to as the placing part.

Thus, the outlet extends along the front edge of the placing part. Alternatively, part of or substantially all the outlets are further towards the rear, for example, halfway or on the rear side of the placing part. The flow direction of these outlets also substantially points upwards in such an embodiment example, that is to say, away from the shelf concerned. The flow direction of an outlet on a rear side of a shelf points, preferably, upwards and forward. Generally, the flow direction of the outlets creates an angle of between 5 and 80 degrees with a plane in which the placing side of the shelf extends. Particularly, this angle amounts to between 15 and 65 degrees and, even more particularly, between 30 and 45 degrees.

Preferably there are only outlets on the top side of the shelves as illustrated in the embodiment example. There are no outlets in the rear, top and side walls of the display unit and in the bottom side of the shelves. This can provide different advantages. For example, this can provide a simpler construction, fewer air ducts would suffice and a smaller quantity of air can be circulated.

Preferably all outlets flow to the storage spaces. Alternatively, there can be an outlet underneath in the chamber in front of the front edge of the shelves. This outlet is directed upwards to form an additional air screen for the air screens of the individual storage spaces.

Although it is a simple and, from a heat transfer perspective, an effective method to provide the shelf of a hollow space in such a way that it defines in its entirety the air discharge space, it is also possible to provide a shelf with ducts for the discharge of air to the outlet. At the bottom of the chamber a shelf is provided in the embodiment example. Alternatively, a fixed bottom can form the underside of the chamber preferably provided with an outlet with a flow direction that points away from the top wall of the fixed bottom.

Although it is advantageous to include the shelves as in the illustrated embodiment in a removable manner in a heating display unit, they can also be provided in a fixed manner in the chamber of the display unit. It is not necessary to provide both side walls as double walls with a side unit(s). It is sufficient to provide one side wall with side units. Instead of a side unit with two pass-through spaces next to each other, these pass-through spaces can also be positioned one after the other or separate upward and downward ducts can have been provided that may not have been integrated in a side unit but have been provided separately or may have been integrated with the rear wall.

Instead of a fan another type of air pump can be provided and the air circulation can also be realised in a natural manner by using the density differences between hot and cold air. In that case, the air temperature regulating elements also act as an air moving apparatus. Preferably the inlet opening will then be provided at a lower level than the outlets.

In the embodiment example at least part of the air moving apparatus and part of the air temperature regulating means are included in the air duct. The air temperature regulating means can also, for example, extend around an air duct or may have been provided somewhere else in or near the air duct, the suction openings or the outlets. The air moving apparatus can also be found in front or in the inlet opening or after the outlet.

Instead of one, multiple suction openings may have been provided. Preferably most of the multiple suction openings are in the horizontal depth direction seen from between the front edge of the top shelf and the front edge of the top wall of the display unit. In the horizontal width direction, one inlet opening or multiple inlet openings extend over substantially the entire width of the display unit.

Alternatively, one or multiple suction openings can be at the bottom of the chamber of the display unit. Because cold ambient air that enters into the chamber via the open front side will drop downwards naturally, relatively cold air is suctioned from the chamber whereby less heat is lost from the chamber. Air can also be suctioned directly from the environment via an inlet opening on the outside of the display unit.

If multiple suction openings are used, the air duct branches towards the suction openings as the air duct branches to the outlets in the illustrated embodiment example. Alternatively, the air duct can comprise multiple individual air ducts that each extend directly from one or multiple suction openings to one or multiple outlets.

The shelves extend substantially horizontally. That is to say, the placing side of the shelf extends in such a plane that goods can be placed on this placing side without them falling thereof. Partitions or other means may have been provided within this context on the placing side of the shelf that contributes towards the goods remaining on the placing side. In the illustrated embodiment example the placing sides of the shelves create an angle of 23 degrees with a horizontal face. In particular, the placing side of the shelf creates an angle of less than 45 degrees with a horizontal face, which is considered to be substantially horizontal for the present invention. The shelves preferably comprise a closed area to impede the exchange of air between two storage spaces that lay one on top of the other.

Due to the air screens according to the invention, the front side of the display unit can remain open during use. To save on energy, the open front side can also be provided with a door to close the open front side temporarily or semipermanently.

FIG. 4 illustrates in perspective view a particular embodiment of the display unit according to the invention. Equal reference numbers match reference numbers in other figures. The display unit illustrated in FIG. 4 has an air circulation system with a fan in a part of the display unit that lies beneath. Via arrows air can be guided from and to the fan. Via a pipe 26 an air flow can be guided to a shelf 12. The top shelf in the figure is illustrated as an exploded view and is further illustrated in FIG. 5.

FIG. 5 illustrates in a perspective exploded view a shelf with a heating element 281. In contrast to the display unit from FIG. 1 with a centrally set-up heating element, each shelf is provided here with an individual heating element 281. The heating element 281 is sheet-shaped and has been set-up in the cavity of the shelf. The heating element extends over substantially the entire width of the shelf 12. The heating element comprises an electric resistance that has been installed on a thermosetting material, for example, Mica, in a net-forming relationship. This will ensure that a flat heating element is obtained that allow an adequate air flow. The heating element is fixed near the bottom side of the shelf so that the bottom side of the shelf is heated more than the top side. In the cavity of the shelf a partition 341 is, furthermore, provided that separates a heating chamber with heating element 281 from a pressure chamber within the cavity. The pressure chamber can be connected to the air supply pipe 26. The air flow of the pressure chamber to the heating chamber is indicated using small arrows 342. The air flow goes via an outlet in the partition. A uniform air flow to the heating chamber can be obtained through a uniform distribution of the outlets.

Thus, the invention provides a display unit for storing goods hot with individual air screens for every storage space. Because the air screens are not directed towards the food to be kept hot, the food is negatively affected less quickly and the packaging of the food can comply with less strict requirements. Individual air screens are, moreover, more effective and can be realised with lower air speeds than a central air screen. By blowing air into the storage spaces, relatively little air is required to keep goods at the required temperature. The display unit according to the invention is, moreover, simple because it only requires one air circulation in which only one inlet opening and one outlet per shelf is required. 

1. Display unit for storing and displaying heated goods wherein the display unit comprises walls, multiple shelves, an air duct, an air forcing apparatus and air temperature regulating means in which at least part of the walls of the display unit delimit a chamber including an open front side; the multiple shelves each comprise an upper placing side; the multiple shelves each extend substantially horizontally in the chamber and are provided above each other to define an individual corresponding storage space above each shelf; the air duct extends from an inlet opening to multiple outlets in which the outlets are positioned at a front edge of the shelf wherein all the outlets define a flow direction of a generated air flow, wherein at least one of the multiple outlets discharges into a corresponding storage space wherein a flow direction of the at least one outlet forms a corresponding placing side that points away to the rear of the corresponding storage space such that substantially the entire air flow flows into the corresponding storage space.
 2. Display unit according to claim 1 wherein the storage space is closed at the rear in such that a generated air flow returns in the storage space and leaves the storage space at the front side of the shelf.
 3. Display unit according to claim 1 wherein the placing side at the upper side of the shelf is airtight.
 4. Display unit according to claim 1 wherein at least one of the shelves comprises a front edge and wherein at least one of the multiple outlets extends along said front edge.
 5. Display unit according to claim 1 wherein the flow direction of at least one outlet that extends along the front edge points upwards and backwards.
 6. Display unit according to claim 1 wherein the shelf comprises a pressure chamber that is in communication with the outlet.
 7. Display unit according to claim 1 wherein at least one shelf comprises a heating element for heating a passing air flow.
 8. Display unit according to claim 7 wherein the heating element has a heat-generating upper and lower side in such a way that heat can be emitted to an upper and lower region.
 9. Display unit according to claim 1 wherein the display unit comprises a heating element in an upper region for heating a passing air flow.
 10. Display unit according to claim 1 wherein at least one outlet is provided in an elongated flow unit that is provided at the front edge of at least one of the shelves.
 11. Display unit according to claim 10 wherein a front wall section of the elongated flow unit is wider than a rear wall section of the elongated flow unit such that the front wall section covers the outlet in a vertical direction.
 12. Display unit according to claim 1 wherein all outlets discharges into the storage spaces.
 13. Method for heating products in a storage or display unit wherein the display unit has a rear wall and side walls and wherein the display unit comprises at least one shelf wherein a storage space is formed on top of the shelf for the storage of products, wherein an air flow is guided through a hollow shelf from the rear to the front and that substantially the entire air flow is supplied to the storage space from a front edge of the shelf.
 14. Method according to claim 13 wherein the air is supplied from the front edge upwards and to the rear in the storage space by at least one outlet.
 15. Method according to claim 13 wherein the supplied air flow in the storage space returns and is discharged at the front side of the storage space.
 16. Method according to claim 15 wherein the discharged air flow is guided upwards on the front side of the display unit.
 17. Method according to claim 13 wherein heat is generated in the storage space by using a heating element and whereby this heat is supplied to a passing air flow in the storage space.
 18. Method according to claim 17 wherein more heat from above is supplied to the air flow in the storage space than from the bottom.
 19. Method according to claim 13, wherein the air flow forms an air screen over a product on the shelf.
 20. Method according to claim 13 wherein the display unit is used for storing pasta hot. 